The Anglo-Scottish border between England and Scotland runs for 96 miles (154 km) between Marshall Meadows Bay on the east coast and the Solway Firth in the west. It is Scotland's only land border with another country, and one of England's two (the other being with Wales).

A 16th-century Act of the Scottish Parliament talks about the chiefs of the border clans, and a late 17th-century statement by the Lord Advocate uses the terms "clan" and "family" interchangeably. Although Lowland aristocrats may have increasingly liked to refer to themselves as "families", the idea that the term "clan" should be used of Highland families alone is a 19th-century convention.[7]

For centuries the Marches on either side of the boundary was an area of mixed allegiances, where families or clans switched which country or side they supported as suited their family interests at that time, and lawlessness abounded. Before the personal union of the two kingdoms under James, the border clans would switch allegiance between the Scottish and English crowns depending on what was most favourable for the members of the clan. For a time a powerful local clan dominated a region on the border between England and Scotland. It was known as the Debatable Lands and neither monarch's writ was heeded.[citation needed]

Following the 1603 Union of the Crowns, King James VI & I decreed that the Borders should be renamed 'the Middle Shires'. In the same year the King placed George Home, 1st Earl of Dunbar in charge of pacification of the borders. Courts were set up in the towns of the Middle Shires and known reivers were arrested. The more troublesome and lower classes were executed without trial; known as "Jeddart justice" (after the town of Jedburgh in Roxburghshire). Mass hanging soon became a common occurrence. In 1605 he established a joint commission of ten members, drawn equally from Scotland and England, to bring law and order to the region. This was aided by statutes in 1606 and 1609, first to repeal hostile laws on both sides of the border, and then to more easily prosecute cross-border raiders.[8] Reivers could no longer escape justice by crossing from England to Scotland or vice versa.[9] The rough-and-ready Border Laws were abolished and the folk of the middle shires found they had to obey the law of the land like all other subjects.

In 1607 James felt he could boast that "the Middle Shires" had "become the navel or umbilic of both kingdoms, planted and peopled with civility and riches". After ten years King James had succeeded; the Middle Shires had been brought under central law and order. By the early 1620s the Borders were so peaceful that the Crown was able to scale down its operations.

Despite these improvements, the Joint Commission continued its work, and as late as 25 September 1641 under King Charles I, Sir Richard Graham, a local laird and English MP, was petitioning the Parliament of Scotland "for regulating the disorders in the borders".[10] Conditions along the border generally deteriorated during the Commonwealth and Protectorate periods, with the development of Moss-trooper raiders. Following the Restoration, on-going border lawlessness was dealt with by reviving former legislation, renewed continually in eleven subsequent acts, for periods ranging from five to eleven years, up until the late 1750s.[8]

The Debatable Lands lay between Scotland and England to the north of Carlisle,[11] the largest population centre being Canonbie.[12] For over three hundred years the area was effectively controlled by local clans, such as the Armstrongs, who successfully resisted any attempt by the Scottish or English governments to impose their authority.[13] In 1552 commissioners met to divide the land in two: Douglas of Drumlanrigg leading the Scots; Lord Wharton leading the English; the French ambassador acting umpire. The Scots' Dike was built as the new frontier, with stones set up bearing the arms of England and of Scotland.[14][15]

At the River Tweed the border runs down the middle of the river, however between the villages of Wark and Cornhill the Scottish border comes south of the river to enclose a small riverside meadow of approximately 2 acres (0.81 hectares) to 3 acres (1.2 hectares). This piece of land is known as the Ba Green. It is said locally that every year the men of Coldstream (to the North of the river) would play the men of Wark (to the South of the river) at ba, and the winning side would claim the Ba Green for their country. As Coldstream grew to have a larger population than Wark, the Coldstream men always defeated the Wark men at the game, and so the land became a permanent part of Scotland.[21][22][23]

It is a common misconception that Hadrian's Wall marks the boundary between England and Scotland. In fact Hadrian's Wall lies entirely within England and has never formed the Anglo-Scottish border.[24][25] While it is less than 0.6 mi (1.0 km) south of the border with Scotland in the west at Bowness-on-Solway, in the east it is as much as 68 miles (109 km) away.

For centuries the Wall was the boundary between the Roman province of Britannia (to the south) and the Celtic lands of Caledonia (to the north). However Britannia occasionally extended as far north as the later Antonine Wall.

Hadrian's wall is often erroneously used as a popular reference to the modern border, especially in humorous contexts.[a]

Cumbria and Northumberland have amongst the largest Scottish-born communities in the world outside Scotland. 16,628 Scottish born people were residing in Cumbria in 2001 (3.41% of the county's population) and 11,435 Scottish born people were residing in Northumberland (3.72% of the county's population); the overall percentage of Scottish-born people in England is 1.62%.[26]

^Act anent fugitive persones of the borders to the in countrey (1609): Forsamekle as the kingis majestie is resolved to purge the mydele schyres of this isle, heirtofoir callit the bordouris of Scotland and England, of that barbarous crueltie, wickednes and incivilitie whilk be inveterat custome almaist wes become naturall to mony of the inhabitantis thairof... (Translated: Forasmuch as the king's majesty is resolved to purge the middle shires of this isle, heretofore called the borders of Scotland and England, of that barbarous cruelty, wickedness and incivility which by inveterate custom almost was become natural to many of the inhabitants thereof...)

^Petition of Sir Richard Graham regarding the middle shires: I am desired by Sir Richard Graham to move your majesty and this house of parliament that some present course may be taken for regulating the disorders that are now in the middle shires, this being the best time whilst the English commissioners are here that order may be given to the commissioners of both kingdoms to call the border landlords now in town to inform themselves what course has been formerly held for the suppressing of disorder and apprehending of felons and fugitives.

^"Swapping sides: the English town that wants to be Scottish". The Independent. 13 February 2008. Archived from the original on 6 July 2008. Retrieved 31 December 2009. It was Berwick which became the focal point for the direct action of one of the first modern Scottish nationalists, Wendy Wood in the 1950s. Controversially...she was regularly arrested for moving the border signs over the Tweed.